Since the launch of Opera 10.5 in March 2010, I've been using it as my primary browser, whether at work or at home.
Using Ubuntu at work, and a Windows netbook at home, I wanted a fast browser for my netbook and a coherent browsing experience on both operating systems. And this is where Opera 10.5 (and newer) fits perfectly.

It took me a while to realize that one existed (and to remember it), and then the third time I tried to use it (after a minor decimal point update), it didn't work any more!

Man, I still remember shortcuts like G (to toggle images off, cached, on) that haven't worked in years. Hell, I'm still tempted to press CTRL + N when I want a new page (yes, I said "page", dammit! Tabs are the little things at the top of... the actual fricking pages! What the hell would I need a new "tab" for?)

Delving into configs to deal with the ever-changing shortcuts in Opera is a PITA (I deal with at least 4 different installs of my own, plus a couple on my GF's comps). If they could Sync that across all instances, that'd be sweet.

In the meantime, I've pretty much given up on learning keyboard shortcuts in Opera. If it works on one install, it won't on another. Or it'll just stop working with the next bloody update.

Even so, Opera's still my go-to browser. FF & Chrome just feel too limited out of the box (and FF too slow, especially when bloated up with add-ons).

None of those shortcuts were short-lived. You may not have discovered them until just before they changed, but they existed for many years before that.

Also, Opera's shortcuts are not always changing. Again you are making a completely bogus claim.

Shortcuts very rarely change in Opera, and when they do, there's a good reason for it. For example, the "g" shortcut ruined pages if you hit it by accident and had no idea how to get back to the regular view.